API Spec 10D-2021 pdf free download

API Spec 10D-2021 pdf free download.Casing Bow-spring Centralizers.
1 Scope This specifcation provides testing, performance, and marking requirements for casing bow-spring centralizers to be used in oil and natural gas well construction. The procedures provide verifcation testing for the manufacturer’s design, materials, and process specifcations, and periodic testing to confrm the consistency of product performance. This specifcation is not applicable to other devices, such as rigid centralizers and cement baskets, or bow-spring centralizers used for other purposes (e.g., wireline tools, gravel pack, inner string). 2 Normative Reference This document contains no normative references. For a listing of other articles associated with this publication, refer to the bibliography. 3? Terms? and? Defnitions,? Symbols,? and? Abbreviations 3.1? Terms? and? Defnitions For the purposes of this specifcation, the following terms and defnitions apply. 3.1.1 annular clearance Radial clearance between the outside diameter of the casing and the wellbore. 3.1.2 API test load Specifed normal force applied to a bow-spring centralizer to evaluate standof performance. 3.1.3 bow-spring centralizer An apparatus comprised of a plurality of bow-shaped springs biased outwardly from a tubular body, the outside diameter of which can vary under a change in applied load, and connected by two end collars, that is placed on the outside of a tubular (e.g., casing or tubing) and used to centralize the tubular in a wellbore. 3.1.4 bow-spring centralizer sub A bow-spring centralizer installed on a tubular body having an integral holding method where the tubular body becomes its own section of the casing string. 3.1.5 casing nominal diameter Theoretical outside diameter of the casing. 3.1.6 conventional application An application where the smallest wellbore diameter that the bow-spring centralizer will pass through is at the centralizer setting depth (see Figure 1).
3.1.8 hole size The diameter of the wellbore at the intended centralizer setting depth. NOTE This includes setting depth in cased hole, open hole, or restriction(s). 3.1.9 open hole The portion of the wellbore that is not cased. 3.1.10 restarting force Maximum force required to restart movement of a bow-spring centralizer inside a specifc wellbore diameter in given conditions and installation methods. 3.1.11 restoring force Normal force exerted by a bow-spring centralizer against the casing to keep it away from the wellbore wall, and equal to the load force required to provide the defection of the bow in given conditions and installation methods. 3.1.12 restriction The smallest diameter through which the bow-spring centralizer is passed in testing. 3.1.13 running force Average force required to move a bow-spring centralizer through a specifed wellbore diameter in given conditions and installation methods. 3.1.14 standoff The smallest distance between the outside diameter of the casing and the wellbore. 3.1.15 standoff ratio The ratio of standof to annular clearance, expressed as a percentage (see Figure 8). NOTE In the feld, standof ratio is commonly referred to as “standof.” 3.1.16 starting force The maximum force required to insert a bow-spring centralizer into a specifed wellbore diameter in given conditions and installation methods. 3.1.17 stop collar A device attached to the casing to limit axial movement of a casing bow-spring centralizer. NOTE This can be either an independent piece of equipment or integral with the bow-spring centralizer. 3.1.18 under-reamed application An application where the bow-spring centralizer passes through a smaller ID in the wellbore prior to reaching the centralizer setting depth (see Figure 1).
4.2 Starting Force The maximum starting force for conventional applications shall be less than the weight of 12.2 m (40 ft) of casing of medium linear mass as defned in Table 1. The maximum starting force shall be determined for a bow-spring centralizer in new, fully assembled condition being run in an outer pipe internal diameter (ID) equal to the hole size. Starting force values for under-reamed applications may be higher. 4.3 Standoff Ratio at API Test Load The minimum standof ratio (SOR) shall not be less than 67 % when the bow-spring centralizer is subjected to the API test load values given in Table 1. Sizes not shown in Table 1 shall conform with 4.3.1.